Generally speaking, mounting brackets for heat exchangers are fixtured preliminary to brazing operations. This is true for a variety of heat exchangers including radiators, condensers and oil coolers. For instance, fixtured brackets are commonly utilized in parallel flow heat exchangers.
In this connection, it has been proposed for certain applications to utilize parallel flow heat exchangers wherein a plurality of parallel tubes extend between headers. Each of the tubes in such an arrangement defines a plurality of parallel flow paths within its innards. With this construction, relatively small individual passages can be utilized which in turn reduces the percentage of the total frontal area of the device occupied by the tubes.
However, forming tubes to contain a plurality of parallel flow paths has presented a number of difficulties, particularly where the flow paths are intended to have a small hydraulic diameter. Economical extrusion techniques have not yet been developed and where inserts are utilized to subdivide the interior of the tube, difficulty has been met. More specifically, this has presented the problem of maintaining the structural integrity of the assemblage to prevent tube rupture at conventional operating pressures.
While this problem has been addressed in commonly owned U.S. Pat. No. 4,688,311, other problems remain in connection with such heat exchangers. Notably, for all heat exchangers, but particularly parallel flow heat exchangers such as radiators, condensers and oil coolers, fixtured brackets which are subjected to a brazing operation have been subject to shifts in location and have been known to lose most of their temper and strength. Of course, this is most undesirable in maintaining the structural integrity of the assemblage particularly as it relates to the tubes, fins and headers.
Accordingly, the present invention is directed to overcoming one or more of the above problems.